Design optimization of a residential scale solar driven adsorption cooling system in upper Egypt based

This study provides a decision support approach for selecting the best size of the main components of a small scale solar assisted, silica gel-water, adsorption cooling system in arid areas located in Assiut, Egypt. To achieve the objective of this work, an optimization based on a computer simulation has been performed on the design variables, which are: solar collector area, the volume of the hot storage tank, the volume of the cold storage tank, and thermostat set point of the auxiliary heating element. Economic and environmental evaluations of the proposed systems have been performed as well. A validation of the model results is performed with the experimental results of solar driven silica gel-water adsorption cooling system at Assiut University Campus which has worked since 2012. The results show that the tilt angle of 5 ° for the surface of the solar collectors achieved the best absorbed solar radiation by the collector filed. For all proposed systems, the solar fraction did not affect the volume of the cold water storage tank while it has a significant effect on the area of the solar collector field and as well as the volume of the hot water storage tank. The initial cost of the proposed systems ranges from 2897 €/kWc to 4808 €/kWc and this can be considered as a hindrance to spreading at the commercial level. Meanwhile, the running cost over a year achieves low values, and it ranges from 13.9 €/kWc to 99.11 €/kWc.The proposed systems of lower solar fraction give lower carbon dioxide emissions. The carbon dioxide emissions range from193 kg of CO2eq./kWc per year for the fully solar driven cooling system to 1062 kg of CO2eq./kWc per year for the cooling system fully driven by natural gas. Based on the solar saving approach the proposed system of 24 m2 solar collector area, 0.6 m3 hot storage tank, and 1 m3 cold storage tank with 94 °C auxiliary heater set-point temperature can be considered as the most economically feasible solution.